Copolycarbonate composition and article containing the same

ABSTRACT

The present invention relates to a copolycarbonate resin composition comprising a copolycarbonate in which a specific siloxane compound is introduced in a main chain of the polycarbonate, and a UV stabilizer. Since the present copolycarbonate resin composition has excellent weather resistance, the article prepared by using this composition exhibits less deteriorated surface quality and physical properties caused by ultraviolet rays or the like when exposed to the outside.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a National Stage Application of International Application No. PCT/KR2015/013159, filed Dec. 3, 2015, and claims the benefit of Korean Patent Application No. 10-2015-0159987, filed Nov. 13, 2015, and Korean Patent Application No. 10-2014-0173005, filed Dec. 4, 2014, the contents of which are incorporated herein by reference in their entirety for all purposes as if fully set forth below.

TECHNICAL FIELD

The present invention relates to a copolycarbonate composition having excellent weather resistance and to an article comprising the same.

BACKGROUND OF ART

Polycarbonate resins are prepared by condensation-polymerization of an aromatic diol such as bisphenol A with a carbonate precursor such as phosgene and have excellent impact strength, dimensional stability, heat resistance and transparency. Thus, the polycarbonate resins have application in a wide range of uses, such as exterior materials of electrical and electronic products, automobile parts, building materials, and optical components.

Recently, in order to apply these polycarbonate resins to more various fields, many studies have been made to obtain desired physical properties by copolymerizing two or more aromatic diol compounds having different structures from each other and introducing units having different structures in a main chain of the polycarbonate.

Products made of polycarbonate resins may have deteriorated surface quality and physical properties caused by ultraviolet rays or the like when exposed to the outside. Thus, the weather resistance that prevents the physical properties of the polycarbonate resin from being decreased by ultraviolet rays or the like is required.

Given the above circumstances, the present inventors have found that a copolycarbonate resin composition comprising a copolycarbonate in which a specific siloxane compound is introduced in a main chain of the polycarbonate and a UV stabilizer as described below has excellent physical properties such as weather resistance, and completed the present invention.

DETAILED DESCRIPTION OF THE INVENTION Technical Problem

It is an object of the present invention to provide a copolycarbonate composition having excellent weather resistance.

It is another object of the present invention to provide an article comprising the above-mentioned copolycarbonate composition.

Technical Solution

In order to achieve the above objects, the present invention provides a copolycarbonate composition which comprises (a) a copolycarbonate which comprises an aromatic polycarbonate-based first repeating unit; and one or more aromatic polycarbonate-based second repeating units having siloxane bonds, and (b) a UV stabilizer, wherein the copolycarbonate composition has ΔYI of not more than 7 as measured according to the following Equation 1: ΔYI=YI(500 hours)−YI(0 hour)  [Equation 1]

in the Equation 1,

YI (0 hour) is YI (Yellow Index) measured in accordance with ASTM D1925 with respect to the copolycarbonate composition, and

YI (500 hours) is YI (Yellow Index) measured in accordance with ASTM 01925 with respect to the copolycarbonate composition, after irradiating ultraviolet rays of 340 nm to the composition with a light quantity of 0.55 w/m² at 60° C. for 500 hours in accordance with ASTM D4329.

When preparing a product using a copolycarbonate, the product may have deteriorated surface quality and physical properties caused by ultraviolet rays or the like when exposed to the outside. Therefore, in order to minimize deterioration of the physical properties caused by ultraviolet rays or the like, a UV stabilizer is used with the copolycarbonate in the present invention.

Hereinafter, the present invention will be described in detail.

Copolycarbonate

The copolycarbonate according to the present invention comprises an aromatic polycarbonate-based first repeating unit; and one or more aromatic polycarbonate-based second repeating units having siloxane bonds.

The above aromatic polycarbonate-based first repeating unit is formed by reacting an aromatic diol compound and a carbonate precursor, and it is more preferably represented by the following Chemical Formula 1:

in the Chemical Formula 1,

R₁, R₂, R₃ and R₄ are each independently hydrogen, C₁₋₁₀ alkyl, C₁₋₁₀ alkoxy, or halogen, and

X is C₁₋₁₀ alkylene unsubstituted or substituted with phenyl, C₃₋₁₅ cycloalkylene unsubstituted or substituted with C₁₋₁₀ alkyl, O, S, SO, SO₂, or CO.

Preferably, in the Chemical Formula 1, R₁, R₂, R₃ and R₄ are each independently hydrogen, methyl, chloro, or bromo.

Also, X is preferably a linear or branched C₁₋₁₀ alkylene unsubstituted or substituted with phenyl, and more preferably methylene, ethane-1,1-diyl, propane-2,2-diyl, butane-2,2-diyl, 1-phenylethane-1,1-diyl, or diphenylmethylene. Further, preferably, X is cyclohexane-1,1-diyl, O, S, SO, SO₂, or CO.

Preferably, the repeating unit represented by Chemical Formula 1 may be derived from one or more aromatic diol compounds selected from the group consisting of bis(4-hydroxyphenyl)methane, bis(4-hydroxyphenyl)ether, bis(4-hydroxyphenyl)sulfone, bis(4-hydroxyphenyl)sulfoxide, bis(4-hydroxyphenyl)sulfide, bis(4-hydroxyphenyl)ketone, 1,1-bis(4-hydroxyphenyl)ethane, bisphenol A, 2,2-bis(4-hydroxyphenyl)butane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 2,2-bis(4-hydroxy-3,5-dibromophenyl)propane, 2,2-bis(4-hydroxy-3,5-dichlorophenyl)propane, 2,2-bis(4-hydroxy-3-bromophenyl)propane, 2,2-bis(4-hydroxy-3-chlorophenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, bis(4-hydroxyphenyl)diphenylmethane, and α,ω-bis[3-(o-hydroxyphenyl)propyl]polydimethylsiloxane.

As used herein, ‘derived from aromatic diol compounds’ means that a hydroxy group of the aromatic diol compound and a carbonate precursor are reacted to form the repeating unit represented by Chemical Formula 1.

For example, when bisphenol A, which is an aromatic diol compound, and triphosgene, which is a carbonate precursor, are polymerized, the repeating unit represented by Chemical Formula 1 is represented by the following Chemical Formula 1-1:

The carbonate precursor used herein may include one or more selected from the group consisting of dimethyl carbonate, diethyl carbonate, dibutyl carbonate, dicyclohexyl carbonate, diphenyl carbonate, ditolyl carbonate, bis(chlorophenyl)carbonate, di-m-cresyl carbonate, dinaphthyl carbonate, bis(diphenyl)carbonate, phosgene, triphosgene, diphosgene, bromophosgene and bishaloformate. Preferably, triphosgene or phosgene may be used.

The above-described one or more aromatic polycarbonate-based second repeating units having siloxane bonds are formed by reacting one or more siloxane compounds and a carbonate precursor, and it comprises preferably a repeating unit represented by the following Chemical Formula 2 and a repeating unit represented by the following Chemical Formula 3:

in the Chemical Formula 2,

each of X₁ is independently C₁₋₁₀ alkylene,

each of R₅ is independently hydrogen; C₁₋₁₅ alkyl unsubstituted or substituted with oxiranyl, oxiranyl-substituted C₁₋₁₀ alkoxy, or C₆₋₂₀ aryl; halogen; C₁₋₁₀ alkoxy; allyl; C₁₋₁₀ haloalkyl; or C₆₋₂₀ aryl, and

n is an integer of 10 to 200,

in the Chemical Formula 3,

each of X₂ is independently C₁₋₁₀ alkylene,

each of Y₁ is independently hydrogen, C₁₋₆ alkyl, halogen, hydroxy, C₁₋₆ alkoxy, or C₆₋₂₀ aryl,

each of R₆ is independently hydrogen; C₁₋₁₅ alkyl unsubstituted or substituted with oxiranyl, oxiranyl-substituted C₁₋₁₀ alkoxy, or C₆₋₂₀ aryl; halogen; C₁₋₁₀ alkoxy; allyl; C₁₋₁₀ haloalkyl; or C₆₋₂₀ aryl, and

m is an integer of 10 to 200.

In Chemical Formula 2, each of X₁ is independently preferably C₂₋₁₀ alkylene, more preferably C₂₋₄ alkylene and most preferably propane-1,3-diyl.

Also, preferably, each of R₅ is independently hydrogen, methyl, ethyl, propyl, 3-phenylpropyl, 2-phenylpropyl, 3-(oxiranylmethoxy)propyl, fluoro, chloro, bromo, iodo, methoxy, ethoxy, propoxy, allyl, 2,2,2-trifluoroethyl, 3,3,3-trifluoropropyl, phenyl, or naphthyl. In addition, each of R₅ is independently preferably C₁₋₁₀ alkyl, more preferably C₁₋₆ alkyl, more preferably C₁₋₃ alkyl and most preferably methyl.

Further, preferably, n is an integer of not less than 10, not less than 15, not less than 20, not less than 25, not less than 30, not less than 31, or not less than 32; and not more than 50, not more than 45, not more than 40, not more than 39, not more than 38, or not more than 37.

In Chemical Formula 3, each of X₂ is independently preferably C₂₋₁₀ alkylene, more preferably C₂₋₆ alkylene and most preferably isobutylene.

Further, preferably, Y₁ is hydrogen.

Further, preferably, each of R₆ is independently hydrogen, methyl, ethyl, propyl, 3-phenylpropyl, 2-phenylpropyl, 3-(oxiranylmethoxy)propyl, fluoro, chloro, bromo, iodo, methoxy, ethoxy, propoxy, allyl, 2,2,2-trifluoroethyl, 3,3,3-trifluoropropyl, phenyl, or naphthyl. Further, preferably, each of R₆ is independently C₁₋₁₀ alkyl, more preferably C₁₋₆ alkyl, more preferably C₁₋₃ alkyl, and most preferably methyl.

Preferably, m is not less than 40, not less than 45, not less than 50, not less than 55, not less than 56, not less than 57, or not less than 58; and not more than 80, not more than 75, not more than 70, not more than 65, not more than 64, not more than 63, or not more than 62.

The repeating unit represented by Chemical Formula 2 and the repeating unit represented by Chemical Formula 3 are derived from a siloxane compound represented by the following Chemical Formula 2-1 and a siloxane compound represented by the following Chemical Formula 3-1, respectively:

in the Chemical Formula 2-1, X₁, R₅ and n are the same as previously defined.

in the Chemical Formula 3-1, X₂, Y₁, R₆ and m are the same as previously defined.

As used herein, ‘derived from a siloxane compound’ means that a hydroxy group of the respective siloxane compound and a carbonate precursor are reacted to form the repeating unit represented by Chemical Formula 2 and the repeating unit represented by the Chemical Formula 3. Further, the carbonate precursors that can be used for the formation of the repeating units represented by Chemical Formulae 2 and 3 are the same as those described for the carbonate precursor that can be used for the formation of the repeating unit represented by Chemical Formula 1 described above.

The methods for preparing the siloxane compound represented by Chemical Formula 2-1 and the siloxane compound represented by Chemical Formula 3-1 are represented by the following Reaction Schemes 1 and 2, respectively:

in the Reaction Scheme 1,

X₁′ is C₂₋₁₀ alkenyl, and

X₁, R₅ and n are the same as previously defined.

in the Reaction Scheme 2,

X₂′ is C₂₋₁₀ alkenyl, and

X₂, Y₁, R₆ and m are the same as previously defined.

In Reaction Scheme 1 and Reaction Scheme 2, the reaction is preferably conducted in the presence of a metal catalyst. As the metal catalyst, a Pt catalyst is preferably used. The Pt catalyst used herein may include one or more selected from the group consisting of Ashby catalyst, Karstedt catalyst, Lamoreaux catalyst, Speier catalyst, PtCl₂(COD), PtCl₂(benzonitrile)₂ and H₂PtBr₆. The metal catalyst may be used in an amount of not less than 0.001 parts by weight, not less than 0.005 parts by weight, or not less than 0.01 parts by weight; and not more than 1 part by weight, not more than 0.1 part by weight, or not more than 0.05 part by weight, based on 100 parts by weight of the compounds represented by Chemical Formulae 7 or 9.

Further, the above reaction temperature is preferably 80 to 100° C. Further, the above reaction time is preferably 1 to 5 hours.

In addition, the compounds represented by Chemical Formulae 7 or 9 may be prepared by reacting an organodisiloxane and an organocyclosiloxane in the presence of an acid catalyst, and n and m may be adjusted by adjusting the amount of the reactants used. The reaction temperature is preferably 50 to 70° C. Also, the reaction time is preferably 1 to 6 hours.

The above organodisiloxane may include one or more selected from the group consisting of tetramethyldisiloxane, tetraphenyldisiloxane, hexamethyldisiloxane and hexaphenyldisiloxane. In addition, the above organocyclosiloxane may include, for example, organocyclotetrasiloxane. As one example thereof, octamethylcyclotetrasiloxane and octaphenylcyclotetrasiloxane or the like can be included.

The above organodisiloxane can be used in an amount of not less than 0.1 parts by weight, or not less than 2 parts by weight; and not more than 10 parts by weight, or not more than 8 parts by weight, based on 100 parts by weight of the organocyclosiloxane.

The above acid catalyst that may be used herein includes one or more selected from the group consisting of H₂SO₄, HClO₄, AlCl₃, SbCl₅, SnCl₄ and acid clay (fuller's earth). Further, the acid catalyst may be used in an amount of not less than 0.1 parts by weight, not less than 0.5 parts by weight, or not less than 1 part by weight; and not more than 10 parts by weight, not more than parts by weight or not more than 3 parts by weight, based on 100 parts by weight of the organocyclosiloxane.

The weight ratio between the repeating unit represented by Chemical Formula 2 and the repeating unit represented by Chemical Formula 3 may be from 1:99 to 99:1. Preferably, the weight ratio is from 3:97 to 97:3, from 5:95 to 95:5, from 10:90 to 90:10, or from 15:85 to 85:15, and more preferably from 20:80 to 80:20. The weight ratio of the above repeating units corresponds to the weight ratio of siloxane compounds, for example the siloxane compound represented by Chemical Formula 2-1 and the siloxane compound represented by Chemical Formula 3-1.

Preferably, the repeating unit represented by Chemical Formula 2 is represented by the following Chemical Formula 2-2:

in the Chemical Formula 2-2, R₅ and n are the same as previously defined. Preferably, R₅ is methyl.

Also, preferably, the repeating unit represented by Chemical Formula 3 is represented by the following Chemical Formula 3-2:

in the Chemical Formula 3-2, R₆ and m are the same as previously defined. Preferably, R₆ is methyl.

Further, the copolycarbonate according to the present invention comprises all of the repeating unit represented by Chemical Formula 1-1, the repeating unit represented by Chemical Formula 2-2, and the repeating unit represented by Chemical Formula 3-2.

The copolycarbonate according to the present invention may be prepared by a preparation method comprising a step of polymerizing the aromatic diol compound, the carbonate precursor and one or more siloxane compounds. The aromatic diol compound, the carbonate precursor and one or more siloxane compounds are the same as previously described.

During the polymerization, one or more siloxane compounds may be used in an amount of not less than 0.1% by weight, not less than 0.5% by weight, not less than 1% by weight, or not less than 1.5% by weight; and not more than 20% by weight, not more than 10% by weight, not more than 7% by weight, not more than 5% by weight, not more than 4% by weight, not more than 3% by weight or not more than 2% by weight, based on 100% by weight in total of the aromatic diol compound, the carbonate precursor and the one or more siloxane compounds. Also, the above aromatic diol compound may be used in an amount of not less than 40% by weight, not less than 50% by weight, or not less than 55% by weight; and not more than 80% by weight, not more than 70% by weight, or not more than 65% by weight, based on 100% by weight in total of the aromatic diol compound, the carbonate precursor and one or more siloxane compounds. The above carbonate precursor may be used in an amount of not less than 10% by weight, not less than 20% by weight, or not less than 30% by weight; and not more than 60% by weight, not more than 50% by weight, or not more than 40 by weight, based on 100% by weight in total of the aromatic diol compound, the carbonate precursor and one or more siloxane compounds.

Further, as the polymerization method, an interfacial polymerization method may be used as one example. In this case, there is an advantage in that the polymerization reaction can be made at low temperature and atmospheric pressure, and it is easy to control the molecular weight. The above interfacial polymerization is preferably conducted in the presence of an acid binder and an organic solvent. Furthermore, the above interfacial polymerization may comprise, for example, the steps of conducting pre-polymerization, then adding a coupling agent and again conducting polymerization. In this case, the copolycarbonate having a high molecular weight may be obtained.

The materials used in the interfacial polymerization are not particularly limited as long as they can be used in the polymerization of polycarbonates. The used amount thereof may be controlled as required.

The acid binding agent may include, for example, alkali metal hydroxides such as sodium hydroxide or potassium hydroxide, or amine compounds such as pyridine.

The organic solvent is not particularly limited as long as it is a solvent that can be usually used in the polymerization of polycarbonate. As one example, halogenated hydrocarbon such as methylene chloride or chlorobenzene may be used.

Further, during the interfacial polymerization, a reaction accelerator, for example, a tertiary amine compound such as triethylamine, tetra-n-butyl ammonium bromide and tetra-n-butylphosphonium bromide or a quaternary ammonium compound or a quaternary phosphonium compound may be further used for accelerating the reaction.

In the interfacial polymerization, the reaction temperature is preferably from 0 to 40° C. and the reaction time is preferably from 10 minutes to 5 hours. Further, during the interfacial polymerization reaction, pH is preferably maintained at 9 or more, or 11 or more.

In addition, the interfacial polymerization may be conducted by further including a molecular weight modifier. The molecular weight modifier may be added before the initiation of polymerization, during the initiation of polymerization, or after the initiation of polymerization.

As the above molecular weight modifier, mono-alkylphenol may be used. As one example, the mono-alkylphenol is, for example, one or more selected from the group consisting of p-tert-butylphenol, p-cumyl phenol, decyl phenol, dodecyl phenol, tetradecyl phenol, hexadecyl phenol, octadecyl phenol, eicosyl phenol, docosyl phenol and triacontyl phenol, and preferably p-tert-butylphenol. In this case, the effect of adjusting the molecular weight is great.

The above molecular weight modifier is contained, for example, in an amount of not less than 0.01 parts by weight, not less than 0.1 parts by weight, or not less than 1 part by weight; and in an amount of not more than 10 parts by weight, not more than 6 parts by weight, or not more than 5 parts by weight, based on 100 parts by weight of the aromatic diol compound. Within this range, the required molecular weight may be obtained.

Further, preferably, the molar ratio of the aromatic polycarbonate-based first repeating unit and one or more aromatic polycarbonate-based second repeating units having siloxane bonds is 1:0.001-0.006 and/or the weight ratio thereof is 1:0.01-0.03.

Further, preferably, the copolycarbonate has a weight average molecular weight of 1,000 to 100,000 g/mol and preferably 15,000 to 35,000 g/mol. More preferably, the above weight average molecular weight (g/mol) is not less than 20,000, not less than 21,000, not less than 22,000, not less than 23,000, not less than 24,000, not less than 25,000, not less than 26,000, not less than 27,000, or not less than 28,000. Also, the above weight average molecular weight (g/mol) is not more than 34,000, not more than 33,000, or not more than 32,000.

UV Stabilizer

The copolycarbonate composition according to the present invention comprises a UV stabilizer in order to improve physical properties, particularly, weather resistance, of the above-mentioned copolycarbonate.

The UV stabilizer used in the present invention is not particularly limited as long as it can improve the weather resistance of the copolycarbonate. Preferably, the UV stabilizer has a benzotriazole structure, and more preferably, it is represented by the following Chemical Formula 4:

in the Chemical Formula 4,

R₇, R₈, R₉ and R₁₀ are each independently hydrogen, hydroxy, halogen, or hydrocarbon group having 1 to 12 carbon atoms,

Y₂ and Y₃ are each independently hydrogen; hydrocarbon group having 1 to 40 carbon atoms, wherein the hydrocarbon group may further comprise a nitrogen atom or an oxygen atom.

Specifically, the UV stabilizer used herein may include one or more selected from the group consisting of 2-(5-methyl-2-hydroxyphenyl)benzotriazole (Tinuvin® P), 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole (Tinuvin® 234), 2-(3,5-di-t-butyl-2-hydroxyphenyl)benzotriazole (Tinuvin® 320), 2-(3-t-butyl-5-methyl-2-hydroxyphenyl)-5-chlorobenzotriazole (Tinuvin® 326), 2-(3′,5′-di-t-butyl-2′-hydroxyphenyl)-5-chlorobenzotriazole (Tinuvin® 327), 2-(3,5-di-t-amyl-2-hydroxyphenyl)benzotriazole (Tinuvin® 328) and 2-(2-hydroxy-5-t-octylphenyl) (Tinuvin® 329).

Copolycarbonate Composition

The copolycarbonate composition according to the present invention comprises the above-mentioned copolycarbonate and UV stabilizer.

Meanwhile, in the present invention, the ‘weather resistance’ is evaluated according to the Equation 1. The Equation 1 refers to the difference between YI (Yellow Index, 0 hour) measured in accordance with ASTM D1925 with respect to the copolycarbonate composition and YI (Yellow Index, 500 hours) measured in accordance with ASTM 01925 with respect to the copolycarbonate composition, after irradiating ultraviolet rays under specific conditions (temperature: 60° C., UV wavelength: 340 nm, light quantity: 0.55 w/m², irradiation time: 500 hours) in accordance with ASTM D4329. Therefore, a smaller value of YI means less deformation, i.e., more excellent weather resistance. The UV irrdiation can be performed by using an apparatus commonly known in the art. As one example, QUV-A Accelerated Weathering Test chamber (manufactured by Q-LAB Corporation) can be used.

Preferably, in the Equation 1, ΔYI is not more than 6.5, not more than 6.0, not more than 5.5, not more than 5.0, not more than 4.5, not more than 4.0, not more than 3.5, or not more than 3.0. Also, a smaller value of ΔYI means excellent weather resistance, and the lower limit thereof is 0, but for example, ΔYI may be not less than 0.1, not less than 0.2, not less than 0.3, not less than 0.4, not less than 0.5, not less than 0.6, not less than 0.7, not less than 0.8, not less than 0.9, or not less than 1.0.

Further, preferably, the copolycarbonate composition has a weight average molecular weight of 1,000 to 100,000 g/mol, more preferably 15,000 to 35,000 g/mol. More preferably, the above weight average molecular weight (g/mol) is not less than 20,000, not less than 21,000, not less than 22,000, not less than 23,000, not less than 24,000, not less than 25,000, not less than 26,000, not less than 27,000, or not less than 28,000. Further, the above weight average molecular weight (g/mol) is not more than 34,000, not more than 33,000, or not more than 32,000.

Further, preferably, the above copolycarbonate composition has impact strength at room temperature of 700 to 1000 J/m as measured at 23° C. in accordance with ASTM D256 (⅛ inch, Notched Izod). More preferably, the above impact strength at room temperature (J/m) is not less than 710, not less than 720, not less than 730, not less than 740, not less than 750, or not less than 760. The above impact strength at room temperature (J/m) is more excellent when the value is higher, and it is not limited to any upper limit. However, as one example, it is not more than 850, not more than 840, not more than 830, not more than 820, not more than 810, not more than 800, or not more than 790.

Further, preferably, the above copolycarbonate composition has impact strength at low temperature of 600 to 800 J/m as measured at −30° C. in accordance with ASTM D256 (⅛ inch, Notched Izod). More preferably, the above impact strength at low temperature (J/m) is not less than 610, not less than 620, not less than 630, not less than 640, or not less than 650. Further, the above impact strength at low temperature (J/m) is more excellent when the value is higher, and it is not limited to any upper limit. As one example, it is not more than 750, not more than 740, not more than 730, not more than 720, not more than 710, not more than 700, or not more than 690.

Further, preferably, the above copolycarbonate composition has MI (melt index) of 5 to 20 g/10 min as measured in accordance with ASTM D1238 (conditions of 300° C. and 1.2 kg). More preferably, MI (g/10 min) is not less than 6, not less than 7, not less than 8, not less than 9, or not less than 10; and not more than 19, not more than 18, not more than 17, not more than 16, or not more than 15.

The copolycarbonate composition according to the present invention can be used together with the polycarbonate as needed to adjust the physical properties of the copolycarbonate. The above polycarbonate is distinguished from the copolycarbonate according to the present invention in that a polysiloxane structure is not introduced in a main chain of the polycarbonate.

Preferably, the above polycarbonate comprises a repeating unit represented by the following Chemical Formula 5:

in the Chemical Formula 5,

R′₁, R′₂, R′₃ and R′₄ are each independently hydrogen, C₁₋₁₀ alkyl, C₁₋₁₀ alkoxy, or halogen,

X′ is C₁₋₁₀ alkylene unsubstituted or substituted with phenyl, C₃₋₁₅ cycloalkylene unsubstituted or substituted with C₁₋₁₀ alkyl, O, S, SO, SO₂ or CO.

Further, preferably, the above polycarbonate has a weight average molecular weight of 15,000 to 35,000 g/mol. More preferably, the above weight average molecular weight (g/mol) is not less than 20,000, not less than 21,000, not less than 22,000, not less than 23,000, not less than 24,000, not less than 25,000, not less than 26,000, not less than 27,000, or not less than 28,000. Further, the above weight average molecular weight (g/mol) is not more than 34,000, not more than 33,000, or not more than 32,000.

The repeating unit represented by Chemical Formula 5 is formed by reacting the aromatic diol compound and the carbonate precursor. The aromatic diol compound and the carbonate precursor that can be used herein are the same as previously described for the repeating unit represented by Chemical Formula 1.

Preferably, R′₁, R′₂, R′₃, R′₄ and X′ in Chemical Formula 5 are the same as previously described for R₁, R₂, R₃, R₄ and X in Chemical Formula 1, respectively.

Further, preferably, the repeating unit represented by Chemical Formula 5 is represented by the following Chemical Formula 5-1:

In the copolycarbonate composition, the weight ratio of the copolycarbonate and the polycarbonate is preferably from 99:1 to 1:99, more preferably from 90:10 to 50:50, and most preferably from 20:80 to 80:20.

Article Comprising the Copolycarbonate Composition

In addition, the present invention provides an article comprising the above-mentioned copolycarbonate composition.

Preferably, the above article is an injection molded article. In addition, the article may further comprise, for example, one or more selected from the group consisting of antioxidants, heat stabilizers, light stabilizers, plasticizers, antistatic agents, nucleating agents, flame retardants, lubricants, impact reinforcing agents, fluorescent brightening agents, ultraviolet absorbers, pigments and dyes.

The method for preparing the article may comprise the steps of mixing the copolycarbonate composition according to the present invention and additives such as antioxidants using a mixer, extrusion-molding the mixture with an extruder to produce a pellet, drying the pellet and then injecting the dried pellet with an injection molding machine.

As described above, since the copolycarbonate composition according to the present invention has excellent weather resistance, the article prepared by using this composition exhibits less deteriorated surface quality and physical properties caused by ultraviolet rays or the like when being exposed to the outside.

Advantageous Effects

As set forth above, since the copolycarbonate composition according to the present invention has excellent weather resistance, the article prepared by using this composition exhibits less deteriorated surface quality and physical properties caused by ultraviolet rays or the like when being exposed to the outside.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Below, preferred embodiments will be provided in order to assist in the understanding of the present disclosure. However, these examples are provided only for illustration of the present invention, and should not be construed as limiting the present invention to these examples.

Preparation Example 1: AP-34

47.60 g (160 mmol) of octamethylcyclotetrasiloxane and 2.40 g (17.8 mmol) of tetramethyldisiloxane were mixed. The mixture was then placed in 3 L flask together with 1 part by weight of an acid clay (DC-A3), relative to 100 parts by weight of octamethylcyclotetrasiloxane, and reacted at 60° C. for 4 hours. After completion of the reaction, the reaction product was diluted with ethyl acetate and quickly filtered using a celite. The repeating unit (n) of the terminal-unmodified polyorganosiloxane thus prepared was 34 when confirmed through ¹H NMR.

To the resulting terminal-unmodified polyorganosiloxane, 4.81 g (35.9 mmol) of 2-allylphenol and 0.01 g (50 ppm) of Karstedt's platinum catalyst were added and reacted at 90° C. for 3 hours. After completion of the reaction, the unreacted siloxane was removed by conducting evaporation under the conditions of 120° C. and 1 torr. The terminal-modified polyorganosiloxane thus prepared was designated as ‘AP-34’. AP-34 was pale yellow oil and the repeating unit (n) was 34 when confirmed through ¹H NMR using a Varian 500 MHz, and further purification was not required.

Preparation Example 2: MB-58

47.60 g (160 mmol) of octamethylcyclotetrasiloxane and 1.5 g (11 mmol) of tetramethyldisiloxane were mixed. The mixture was then introduced in 3 L flask together with 1 part by weight of an acid clay (DC-A3), relative to 100 parts by weight of octamethylcyclotetrasiloxane, and reacted at 60 CC for 4 hours. After completion of the reaction, the reaction product was diluted with ethyl acetate and quickly filtered using a celite. The repeating unit (m) of the terminal-unmodified polyorganosiloxane thus prepared was 58 when confirmed through ¹H NMR.

To the resulting terminal-unmodified polyorganosiloxane, 6.13 g (29.7 mmol) of 3-methylbut-3-enyl 4-hydroxybenzoate and 0.01 g (50 ppm) of Karstedt's platinum catalyst were added and reacted at 90° C. for 3 hours. After completion of the reaction, the unreacted siloxane was removed by conducting evaporation under the conditions of 120° C. and 1 torr. The terminal-modified polyorganosiloxane thus prepared was designated as ‘MB-58’. MB-58 was pale yellow oil and the repeating unit (m) was 58 when confirmed through ¹H NMR using a Varian 500 MHz, and further purification was not required.

Preparation Example 3: EU-50

47.60 g (160 mmol) of octamethylcyclotetrasiloxane and 1.7 g (13 mmol) of tetramethyldisiloxane were mixed. The mixture was then placed in 3 L flask together with 1 part by weight of an acid clay (DC-A3), relative to 100 parts by weight of octamethylcyclotetrasiloxane, and reacted at 60° C. for 4 hours. After completion of the reaction, the reaction product was diluted with ethyl acetate and quickly filtered using a celite. The repeating unit (n) of the terminal-unmodified polyorganosiloxane thus prepared was 50 when confirmed through ¹H NMR.

To the resulting terminal-unmodified polyorganosiloxane, 6.13 g (29.7 mmol) of Eugenol and 0.01 g (50 ppm) of Karstedt's platinum catalyst were added and reacted at 90° C. for 3 hours. After completion of the reaction, the unreacted siloxane was removed by conducting evaporation under the conditions of 120° C. and 1 torr. The terminal-modified polyorganosiloxane thus prepared was designated as ‘EU-50’. EU-50 was pale yellow oil and the repeating unit (n) was 50 when confirmed through ¹H NMR using a Varian 500 MHz, and further purification was not required.

Preparation Example 4: Preparation of Polycarbonate (PC)

1784 g of water, 385 g of NaOH and 232 g of BPA (bisphenol A) were added to a polymerization reactor, and dissolved with mixing under a N₂ atmosphere. 4.3 g of PTBP (para-tert butylphenol) and 128 g of TPG (triphosgene) were dissolved in MC (methylene chloride) and a dissolved TPG solution was added thereto and reacted for 1 hour while maintaining pH of the TPG solution at 11 or more. After 10 minutes, 46 g of TEA (triethylamine) was added thereto to conduct a coupling reaction. After a total reaction time of 1 hour and 20 minutes, pH was lowered to 4 to remove TEA, and then pH of a produced polymer was adjusted to neutral pH of 6 to 7 by washing three times with distilled water. The polymer thus obtained was re-precipitated in a mixed solution of methanol and hexane, and then dried at 120° C. to give a final polycarbonate. The polycarbonate thus prepared was designated as ‘PC’.

Example 1

(Step 1)

1784 g of water, 385 g of NaOH and 232 g of BPA (bisphenol A) were added to a polymerization reactor, and dissolved with mixing under a N₂ atmosphere. 4.3 g of PTBP (para-tert butylphenol) and the mixture (weight ratio: 90:10) of 5.91 g of AP-34 prepared in Preparation Example 1 and 0.66 g of MB-58 prepared in Preparation Example 2 were dissolved in MC (methylene chloride) and then added thereto. Subsequently, 128 g of TPG (triphosgene) was dissolved in MC and a dissolved TPG solution was added thereto and reacted for 1 hour while maintaining pH of the TPG solution at 11 or more. After 10 minutes, 46 g of TEA (triethylamine) was added thereto to conduct a coupling reaction. After a total reaction time of 1 hour and 20 minutes, pH was lowered to 4 to remove TEA, and then pH of a produced polymer was adjusted to neutral pH of 6 to 7 by washing three times with distilled water. The polymer thus obtained was re-precipitated in a mixed solution of methanol and hexane, and then dried at 120° C. to give a final copolycarbonate.

(Step 2)

Based on 100 parts by weight of the copolycarbonate prepared in Step 1, 0.3 part by weight of Tinuvin® 329 as a UV stabilizer was mixed to prepare the desired copolycarbonate composition.

Example 2

80 parts by weight of the copolycarbonate prepared in Step 1 of Example 1, 20 parts by weight of the polycarbonate (PC) prepared in Preparation Example 4 and 0.3 part by weight of Tinuvin® 329 as a UV stabilizer were mixed to prepare the desired copolycarbonate composition.

Example 3

100 parts by weight of the copolycarbonate prepared in Step 1 of Example 1 and 0.2 part by weight of Tinuvin® 329 as a UV stabilizer were mixed to prepare the desired copolycarbonate composition.

Comparative Example 1

The copolycarbonate prepared in Step 1 of Example 1 was referred to as Comparative Example 1.

Comparative Example 2

The copolycarbonate was prepared in the same manner as in Step 1 of Example 1, except that 6.57 g of polyorganosiloxane (100 wt % of polyorganosiloxane (EU-50) of Preparation Example 3) was used. The copolycarbonate was referred to as Comparative Example 2.

Comparative Example 3

Based on 100 parts by weight of the copolycarbonate prepared in Comparative Example 2, 0.3 part by weight of Tinuvin®329 as a UV stabilizer was mixed to prepare the desired copolycarbonate composition. This composition was referred to as Comparative Example 3.

Comparative Example 4

The polycarbonate (PC) prepared in Preparation Example 4 was referred to as Comparative Example 4.

The content of the main components used in the examples and comparative examples are shown in Table 1 below.

TABLE 1 Ex.1 Ex.2 Ex.3 C.Ex.1 C.Ex.2 C.Ex.3 C.Ex.4 AP-34 5.91 g Example 1 Example 1³⁾ 5.91 g — — — MB-58 0.66 g and 0.66 g — — — Eu-50 — Preparation — 6.57 g 6.57 g — BPA 232 g example 4²⁾ 232 g 232 g 232 g 232 g TPG 128 g 128 g 128 g 128 g 128 g PTBP 4.3 g 4.3 g 4.3 g 4.3 g 4.3 g UV stabilizer¹⁾ 0.3 0.3 0.2 — — 0.3 — (part by weight) ¹⁾Tinuvin ® 329, the content relative to 100 parts by weight of copolycarbonate ²⁾80 parts by weight of copolycarbonate prepared in Step 1 of Example 1, and 20 parts by weight of polycarbonate prepared in Preparation Example 4 ³⁾100 parts by weight of copolycarbonate prepared in Steo 2 if Example 1

Experimental Example

To the respective copolycarbonate composition prepared in the Examples and Comparative Examples, 0.050 parts by weight of tris(2,4-di-tert-butylphenyl)phosphite, 0.010 parts by weight of octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and 0.030 parts by weight of pentaerythritol tetrastearate were added thereto, and the resulting mixture was pelletized using a 030 mm twin-screw extruder provided with a vent, and was injection-molded at a cylinder temperature of 300° C. and a mold temperature of 80° C. using an injection molding machine N-20C (manufactured by JSW, Ltd.) to prepare a molded specimen.

The characteristics of the above specimens were determined by the following method and the results were shown in Table 2 below.

1) Weight average molecular weight (g/mol): measured using PC standard with Agilent 1200 series.

2) Impact strength at room temperature and impact strength at low temperature: measured at 23° C. and −30° C. in accordance with ASTM D256 (⅛ inch, Notched Izod).

3) Melt index (MI, g/10 min): measured in accordance with ASTM D1238 (conditions of 300° C. and 1.2 kg).

4) Weather resistance (ΔYI): After injection-molding the specimen (width/length/thickness=60 mm/40 mm/3 mm) at 300° C., YI (Yellow Index) was measured using Color-Eye 7000A (manufactured by X-Rite Ltd.) in accordance with ASTM D1925. Then, after residing the specimen in QUV-A Accelerated Weathering Test chamber (manufactured by Q-LAB Corporation, temperature: 60° C., UV wavelength: 340 nm, light quantity: 0.55 w/m²) for 500 hours) in accordance with ASTM D4329, YI (Yellow Index, 500 hours) was measured using Color-Eye 7000A (manufactured by X-Rite Ltd.) in accordance with ASTM D1925. The difference between YI (500 hours) and YI (0 hour) was calculated. Meanwhile, the measurement conditions of YI (Yellow Index) are as follows:

-   -   Measurement temperature: room temperature (23° C.)     -   Aperture size: Large area of view     -   Measurement method: transmittance was measured in a spectral         range (360 nm to 750 nm).

TABLE 2 Unit Ex.1 Ex.2 Ex.3 C.Ex.1 C.Ex.2 C.Ex.3 C.Ex.4 Weight average g/mol 29400 28600 29100 29500 30300 30100 28700 molecular weight Impact strength J/m 781 776 779 823 748 699 850 at room temperature Impact strength J/m 669 653 661 711 636 591 110 at low- temperature Melt Index g/10 min 12 14 13 11 10 11 14 Weather — 3.2 2.9 3.4 20.3 25.4 7.6 18.9 resistance

As shown in Table 2 above, it could be confirmed that examples according to the present invention exhibited significantly excellent weather resistance as compared with comparative examples. In particular, it could be confirmed that the examples according to the present invention have remarkably excellent effects of improving weather resistance, compared with comparative Examples in which the UV stabilizer was not included. In addition, it could be confirmed that, the examples according to the present invention had significantly excellent weather resistance, compared with Comparative Example 3 in which UV stabilizer was included but different copolycarbonate was used. 

The invention claimed is:
 1. A copolycarbonate composition comprising: (a) a copolycarbonate comprising an aromatic polycarbonate-based first repeating unit; and one or more aromatic polycarbonate-based second repeating units having siloxane bonds, and (b) a UV stabilizer, wherein the copolycarbonate composition has ΔYI of not more than 7 as measured according to the following Equation 1: ΔYI=YI(500 hours)−YI(0 hour)  [Equation 1] in the Equation 1, YI (0 hour) is YI (Yellow Index) measured in accordance with ASTM D1925 with respect to the copolycarbonate composition, and YI (500 hours) is YI (Yellow Index) measured in accordance with ASTM D1925 with respect to the copolycarbonate composition, after irradiating ultraviolet rays of 340 nm to the composition with a light quantity of 0.55 w/m² at 60° C. for 500 hours in accordance with ASTM D4329, wherein the second repeating unit comprises a repeating unit represented by Chemical Formula 2 and a repeating unit represented by Chemical Formula 3:

in Chemical Formula 2, each of X₁ is independently C₁₋₁₀ alkylene, each of R₅ is independently hydrogen; C₁₋₁₅ alkyl unsubstituted or substituted with oxiranyl, oxiranyl-substituted C₁₋₁₀ alkoxy, or C₆₋₂₀ aryl; halogen; C₁₋₁₀ alkoxy; allyl; C₁₋₁₀ haloalkyl; or C₆₋₂₀ aryl, and n is an integer of 10 to 200,

in Chemical Formula 3, each of X₂ is independently C₁₋₁₀ alkylene, each of Y₁ is independently hydrogen, C₁₋₆ alkyl, halogen, hydroxy, alkoxy, or C₆₋₂₀ aryl, each of R₆ is independently C₁₋₁₅ alkyl substituted with oxiranyl, oxiranyl-substituted C₁₋₁₀ alkoxy, or C₆₋₂₀ aryl; halogen; C₁₋₁₀ alkoxy; allyl; C₁₋₁₀ haloalkyl; or C₆₋₂₀ aryl, and m is an integer of 10 to 200, and wherein the UV stabilizer is represented by Chemical Formula 4:

in Chemical Formula 4, R₇, R₈, R₉ and R₁₀ are each independently hydrogen, hydroxy, halogen, or hydrocarbon group having 1 to 12 carbon atoms, and Y₂ and Y₃ are each independently hydrogen; hydrocarbon group having 1 to 40 carbon atoms, wherein the hydrocarbon group may further comprise a nitrogen atom or an oxygen atom.
 2. The copolycarbonate composition of claim 1, wherein ΔYI is not more than 3.5.
 3. The copolycarbonate composition of claim 1, wherein the copolycarbonate has a weight average molecular weight of 1,000 to 100,000 g/mol.
 4. The copolycarbonate composition of claim 1, wherein the copolycarbonate composition further comprises a polycarbonate.
 5. The copolycarbonate composition of claim 4, wherein a polysiloxane structure is not introduced in a main chain of the polycarbonate.
 6. The copolycarbonate composition of claim 4, wherein the polycarbonate comprises a repeating unit represented by the following Chemical Formula 5:

in the Chemical Formula 5, R′₁, R′₂, R′₃ and R′₄ are each independently hydrogen, C₁₋₁₀ alkyl, C₁₋₁₀ alkoxy, or halogen, X′ is C₁₋₁₀ alkylene unsubstituted or substituted with phenyl, C₃₋₁₅ cycloalkylene unsubstituted or substituted with C₁₋₁₀ alkyl, O, S, SO, SO₂ or CO.
 7. The copolycarbonate composition of claim 1, wherein the first repeating unit is represented by the following Chemical Formula 1:

in the Chemical Formula 1, R₁, R₂, R₃ and R₄ are each independently hydrogen, C₁₋₁₀ alkyl, C₁₋₁₀ alkoxy, or halogen, and X is alkylene unsubstituted or substituted with phenyl, cycloalkylene unsubstituted or substituted with C₁₋₁₀ alkyl, O, S, SO, SO₂, or CO.
 8. The copolycarbonate composition of claim 7, wherein the repeating unit represented by the Chemical Formula 1 is derived from one or more aromatic diol compounds selected from the group consisting of bis(4-hydroxyphenyl)methane, bis(4-hydroxyphenyl)ether, bis(4-hydroxyphenyl)sulfone, bis(4-hydroxyphenyl)sulfoxide, bis(4-hydroxyphenyl)sulfide, bis(4-hydroxyphenyl)ketone, 1,1-bis(4-hydroxyphenyl)ethane, bisphenol A, 2,2-bis(4-hydroxyphenyl)butane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 2,2-bis(4-hydroxy-3,5-dibromophenyl)propane, 2,2-bis(4-hydroxy-3,5-dichlorophenyl)propane, 2,2-bis(4-hydroxy-3-bromophenyl)propane, 2,2-bis(4-hydroxy-3-chlorophenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, and 1,1-bis(4-hydroxyphenyl)-1-phenylethane, bis(4-hydroxyphenyl)diphenylmethane.
 9. The copolycarbonate composition of claim 7, wherein the repeating unit represented by Chemical Formula 1 is represented by the following Chemical Formula 1-1:


10. The copolycarbonate composition of claim 1, wherein a weight ratio of the repeating unit represented by Chemical Formula 2 and the repeating unit represented by Chemical Formula 3 is 1:99 to 99:1.
 11. The polycarbonate composition of claim 1, wherein the repeating unit represented by Chemical Formula 2 is represented by the following Chemical Formula 2-2:


12. The polycarbonate composition of claim 1, wherein the repeating unit represented by Chemical Formula 3 is represented by the following Chemical Formula 3-2: 